U.S. patent number 10,241,451 [Application Number 15/873,276] was granted by the patent office on 2019-03-26 for fixing apparatus and image forming apparatus.
This patent grant is currently assigned to KONICA MINOLTA, INC.. The grantee listed for this patent is KONICA MINOLTA, INC.. Invention is credited to Mamoru Fukaya, Toru Hayase, Hideaki Ikeda, Masanori Murakami.
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United States Patent |
10,241,451 |
Murakami , et al. |
March 26, 2019 |
Fixing apparatus and image forming apparatus
Abstract
A fixing apparatus includes: an endless fixing belt; a pad
member having a receiving surface and a supported surface; a
pressing rotator pressing the fixing belt against the receiving
surface and forming a nip portion between an outer circumferential
surface of the fixing belt and the pressing rotator; a supporting
member supporting the pad member; and a heating source to heat the
fixing belt. The supporting member includes a base abutting on the
supported surface of the pad member, and an erected wall erected
from the base to partition a space inside the fixing belt into an
upstream space and a downstream space. The erected wall is disposed
upstream or downstream in a recording-material transport direction,
from an intermediate position of the nip portion. The heating
source is disposed in a larger one of the upstream space and the
downstream space.
Inventors: |
Murakami; Masanori (Toyohashi,
JP), Hayase; Toru (Toyokawa, JP), Fukaya;
Mamoru (Nagoya, JP), Ikeda; Hideaki (Toyokawa,
JP) |
Applicant: |
Name |
City |
State |
Country |
Type |
KONICA MINOLTA, INC. |
Chiyoda-ku, Tokyo |
N/A |
JP |
|
|
Assignee: |
KONICA MINOLTA, INC. (Tokyo,
JP)
|
Family
ID: |
61022222 |
Appl.
No.: |
15/873,276 |
Filed: |
January 17, 2018 |
Prior Publication Data
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|
|
Document
Identifier |
Publication Date |
|
US 20180217540 A1 |
Aug 2, 2018 |
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Foreign Application Priority Data
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|
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Feb 1, 2017 [JP] |
|
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2017-016593 |
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Current U.S.
Class: |
1/1 |
Current CPC
Class: |
G03G
15/2053 (20130101); G03G 15/206 (20130101); G03G
15/2028 (20130101); G03G 15/2039 (20130101); G03G
15/2064 (20130101); G03G 2215/2035 (20130101); G03G
15/2042 (20130101) |
Current International
Class: |
G03G
21/00 (20060101); G03G 15/20 (20060101) |
References Cited
[Referenced By]
U.S. Patent Documents
Foreign Patent Documents
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2453318 |
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May 2012 |
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EP |
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2645179 |
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Oct 2013 |
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EP |
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2010276971 |
|
Dec 2010 |
|
JP |
|
Other References
Extended European Search Report dated Jun. 27, 2018 issued in
counterpart European Application No. 18152961.1. cited by
applicant.
|
Primary Examiner: Ngo; Hoang X
Attorney, Agent or Firm: Holtz, Holtz & Volek PC
Claims
What is claimed is:
1. A fixing apparatus which fixes a toner image on a recording
material, the fixing apparatus comprising: an endless fixing belt;
a pad member having (i) a receiving surface facing an inner
circumferential surface of the fixing belt, and (ii) a supported
surface located opposite to the receiving surface; a pressing
rotator disposed to face an outer circumferential surface of the
fixing belt, and forming a nip portion between the pressing rotator
and the outer circumferential surface of the fixing belt, the
recording material being transported through the nip portion; a
supporting member supporting the pad member; and a heating source
to heat the fixing belt, wherein the pressing rotator is
rotationally driven, in a state of pressing the fixing belt in a
pressing direction toward the receiving surface, to cause the
fixing belt to rotate following rotation of the pressing rotator
and to slide on the receiving surface, wherein the supporting
member includes: a base having a flat plate shape, disposed in a
space inside the fixing belt, and abutting on the supported
surface, and an erected wall having a flat plate shape and erected
from the base in a direction away from a position of the pressing
rotator, the erected wall partitioning the space inside the fixing
belt into an upstream space located upstream in a
recording-material transport direction in which the recording
material is transported, and a downstream space located downstream
in the recording-material transport direction, wherein the erected
wall is disposed upstream or downstream in the recording-material
transport direction, from an intermediate position of the nip
portion in the recording-material transport direction, wherein the
heating source is disposed in a larger one of the upstream space
and the downstream space, and wherein the heating source is
disposed between opposite ends of the pad member in the
recording-material transport direction, as seen in the pressing
direction.
2. The fixing apparatus according to claim 1, wherein: a center
position of the heating source in the pressing direction is located
between opposite ends of the erected wall in the pressing
direction, as seen in the recording-material transport
direction.
3. The fixing apparatus according to claim 1, wherein: the healing
source includes a plurality of rod-like heaters each extending in a
direction parallel with an axial direction of the pressing rotator,
and the plurality of rod-like heaters are arranged in the pressing
direction.
4. The fixing apparatus according to claim 3, wherein: the
plurality of rod-like heaters each have a center position in the
pressing direction, and the center position is located between
opposite ends of the erected wall in the pressing direction, as
seen in the recording-material transport direction.
5. The fixing apparatus according to claim 3, wherein: the
plurality of rod-like heaters consist of: a short heater which
generates heat from only a region corresponding to a central
portion of the pressing rotator in the axial direction of the
pressing rotator; and a long heater which generates heat from a
region corresponding to a substantially whole region of the
pressing rotator in the axial direction, and a distance from the
pressing rotator to the long heater is longer than a distance from
the pressing rotator to the short heater.
6. The fixing apparatus according to claim 1, wherein: a
high-reflectance member having a surface with a reflectance higher
than a reflectance of a surface of the supporting member is
attached to at least a part of the surface, facing the heating
source, of the supporting member.
7. The fixing apparatus according to claim 6, wherein: the
high-reflectance member is attached to at least a part of a
surface, facing the heating source, of the erected wall.
8. The fixing apparatus according to claim 1, wherein: at least a
part of a surface, facing the heating source, of the supporting
member is formed of a high-reflectance surface higher in
reflectance than a remaining part of the surface of the supporting
member.
9. The fixing apparatus according to claim 8, wherein: at least a
part of a surface, facing the heating source, of the erected wall
is formed of the high-reflectance surface.
10. The fixing apparatus according to claim 1, wherein: the
supporting member has an L-shaped cross section extending
continuously from one end of the base in the recording-material
transport direction to one end of the erected wall in the pressing
direction.
11. The fixing apparatus according to claim 1, wherein: the
supporting member includes, in addition to the erected wall, a
reinforcing auxiliary wall erected from the base.
12. The fixing apparatus according to claim 1, wherein: the
supporting member is formed of a single member.
13. The fixing apparatus according to claim 1, wherein: the erected
wall is disposed upstream in the recording-material transport
direction from the intermediate position of the nip portion in the
recording-material transport direction, and the heating source is
disposed in the downstream space.
14. The fixing apparatus according to claim 13, further comprising:
a temperature sensor to detect a temperature of the fixing belt;
and a controller to control operation of the heating source based
on the temperature detected by the temperature sensor, wherein the
temperature sensor is disposed to face an outer circumferential
surface of a second specific portion for detecting a temperature of
the second specific portion, the second specific portion is a
portion of the fixing belt, and the portion defines the upstream
space.
15. An image forming apparatus comprising the fixing apparatus
according to claim 1 for use in image formation.
Description
The entire disclosure of Japanese Patent Application No.
2017-016593 filed on Feb. 1, 2017 is incorporated herein by
reference in its entirety.
BACKGROUND
Technological Field
The present disclosure relates to a fixing apparatus that causes a
toner image formed on a recording material such as paper to be
thermally fixed on the recording material, and also relates to an
image forming apparatus such as copier, printer, or facsimile
including the fixing apparatus installed in an image formation unit
forming an image by means of electrophotography. The image forming
apparatus is not limited to a specific type such as color or
monochrome one.
Description of the Related Art
Generally, as a fixing apparatus included in an electrophotographic
image forming apparatus, a fixing apparatus based on a thermal
fixing system is used for the sake of thermal efficiency and
safety. This fixing apparatus applies heat and pressure to a
recording material on which a toner image is formed, to thereby fix
the toner image on the recording material. In the fixing apparatus
based on the thermal fixing system, usually a recording material on
which a toner image is formed is held between a heating rotator and
a pressing rotator so as to thermally fix the toner image on the
recording material.
Heating rotators configured in different manners are known. Among
them, a healing rotator for which an endless fixing belt is used is
known. The heating rotator for which the fixing belt is used is
configured in the form of a fixing belt unit. The fixing belt unit
includes, in addition to the fixing belt, a pad member against
which the fixing belt is pressed by the pressing rotator, a
supporting member supporting the pad member, and a heating source
heating the fixing belt, for example. These components are
assembled into the fixing belt unit.
For example, Japanese Laid-Open Patent Publication No. 2010-276971
discloses a fixing apparatus including a fixing belt unit as
described above that serves as a heating rotator. In the space
inside the fixing belt of the fixing belt unit disclosed in the
aforementioned publication, the pad member, the supporting member,
and the heating source, for example, are arranged.
It is important for the fixing apparatus to have a heating rotator
configured to be compact for the sake of energy saving. This is for
the following reasons. The compactness of the heating rotator
enables reduction of the thermal capacity of the heating rotator
and thereby enables the heating rotator to be heated with less
thermal energy. As the heating rotator is compact, its surface area
is small, which enables prevention of useless heat dissipation.
In the fixing belt unit disclosed in the above-identified
publication, the space inside the fixing belt is substantially
divided into two equal spaces by the supporting member, and the
heating source is disposed in one of the two spaces. In this case,
because the heating source has a considerably large size, the size
of the entire fixing belt unit is inevitably large. In the case
where the fixing belt unit configured in the above-described manner
is used, energy cannot be saved sufficiently.
SUMMARY
An object of the present disclosure is to provide a compact fixing
apparatus appropriate for energy saving as well as an image forming
apparatus including the fixing apparatus.
In order to achieve the above object, a fixing apparatus according
to the present disclosure causes a toner image formed on a
recording material to be fixed on the recording material. The
fixing apparatus includes a fixing belt, a pad member, a pressing
rotator, a supporting member, and a heating source. The fixing belt
is endless. The pad member has a receiving surface facing an inner
circumferential surface of the fixing belt and a supported surface
located opposite to the receiving surface. The pressing rotator is
disposed to face an outer circumferential surface of the fixing
belt, and forms a nip portion between the pressing rotator and the
outer circumferential surface of the fixing belt. The recording
material is transported through the nip portion. The supporting
member supports the pad member, and the heating source heats the
fixing belt. The pressing rotator is rotationally driven, in a
state of pressing the fixing belt in a pressing direction toward
the receiving surface, to cause the fixing belt to rotate following
rotation of the pressing rotator and to slide on the receiving
surface. The supporting member includes: a base having a flat plate
shape, disposed in a space inside the fixing belt, and abutting on
the supported surface, and an erected wall having a flat plate
shape and erected from the base in a direction away from a position
of the pressing rotator. The erected wall partitions the space
inside the fixing belt into an upstream space located upstream in a
recording-material transport direction in which the recording
material is transported, and a downstream space located downstream
in the recording-material transport direction. The erected wall is
disposed upstream or downstream in the recording-material transport
direction, from an intermediate position of the nip portion in the
recording-material transport direction. The heating source is
disposed m a larger one of the upstream space and the downstream
space.
The foregoing and other objects, features, aspects and advantages
of the present invention will become more apparent from the
following detailed description of the present invention when taken
in conjunction with the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
The advantages and features provided by one or more embodiments of
the invention will become more fully understood from the detailed
description given hereinbelow and the appended drawings which are
given by way of illustration only, and thus are not intended as a
definition of the limits of the present invention.
FIG. 1 is a schematic diagram of an image forming apparatus in a
first embodiment.
FIG. 2 is a schematic cross-sectional view of a fixing apparatus in
the first embodiment.
FIG. 3 is a schematic partially-cutaway plan view of the fixing
apparatus shown in FIG. 2.
FIG. 4 is an exploded perspective view of a pad member and a
supporting member shown in FIGS. 2 and 3.
FIG. 5 is a diagram for illustrating an additional feature of a
configuration of the fixing apparatus shown in FIG. 2.
FIG. 6 is a diagram for illustrating another additional feature of
the configuration of the fixing apparatus shown in FIG. 2.
FIG. 7 is a diagram for illustrating still another additional
feature of the configuration of the fixing apparatus shown in FIG.
2.
FIG. 8 is a schematic cross-sectional view of a fixing apparatus in
a second embodiment.
FIG. 9 is a schematic cross-sectional view of a fixing apparatus in
a third embodiment.
FIG. 10 is a schematic cross-sectional view of a fixing apparatus
in a fourth embodiment.
FIG. 11 is a schematic cross-sectional view of a fixing apparatus
in a fifth embodiment.
FIG. 12 is a diagram for illustrating an additional feature of a
configuration of the fixing apparatus shown in FIG. 11.
FIG. 13 is a diagram for illustrating another additional feature of
the configuration of the fixing apparatus shown in FIG. 11.
FIG. 14 is a diagram for illustrating still another additional
feature of the configuration of the fixing apparatus shown in FIG.
11.
DETAILED DESCRIPTION OF EMBODIMENTS
Hereinafter, one or more embodiments will be described with
reference to the drawings. However, the scope of the invention is
not limited to the disclosed embodiments.
In connection with the embodiments illustrated below, a so-called
tandem-type color printer based on electrophotography and a fixing
apparatus included in the color printer are described by way of
example, as an image forming apparatus and a fixing apparatus to
which the present invention is applied. In the following
embodiments, the same or common components are denoted by the same
reference characters in the drawings, and the description thereof
is not repeated.
First Embodiment
FIG. 1 is a schematic diagram of an image forming apparatus in the
first embodiment. Referring to FIG. 1, a general configuration of
image forming apparatus 1 in the present embodiment is
described.
As shown in FIG. 1, image forming apparatus 1 mainly includes an
apparatus body 2 and a paper feed unit 9. Apparatus body 2 includes
an image forming section 2A for forming an image on a sheet of
paper which is fed as a recording material, and a paper feed
section 2B for feeding a sheet of paper to image forming section
2A. Paper feed unit 9 contains sheets of paper to be fed to image
forming section 2A and is removably disposed in paper feed section
2B.
In image forming apparatus 1, various rollers 3 are disposed in
image forming section 2A and paper feed section 2B to form a
transport path 4 through which a sheet of paper is transported in a
predetermined direction. As shown, a manual feed tray 9a may be
disposed separately for feeding a sheet of paper to image forming
section 2A.
Image forming section 2A mainly includes an image generation unit 5
capable of forming respective a toner image of yellow (Y), magenta
(M), cyan (C), and black (K), an exposure unit 6 for exposing a
photoreceptor included in image generation unit 5, an intermediate
transfer belt 7a wound and held in image generation unit 5, a
transfer unit 7 disposed on transport path 4 so that transfer unit
7 is located on a path along which intermediate transfer belt 7a
runs, and a fixing apparatus 8A in the present embodiment described
later herein. Fixing apparatus 8A is disposed on transport path 4
and located downstream of transfer unit 7.
Image generation unit 5 forms a toner image of yellow (Y), magenta
(M), cyan (C), and black (K), or a toner image of black (K) only,
through exposure by exposure unit 6, and transfers the toner image
to intermediate transfer belt 7a (so-called primary transfer).
Accordingly, on intermediate transfer belt 7a, a color toner image
or a monochrome toner image is formed.
Intermediate transfer belt 7a carries, to transfer unit 7, the
color toner image or monochrome toner image formed on the surface
of intermediate transfer belt 7a. At transfer unit 7, the toner
image is pressed together with a sheet of paper transported from
paper feed section 2B to transfer unit 7. Accordingly, the color
toner image or monochrome toner image formed on the surface of
intermediate transfer belt 7a is transferred to the sheet of paper
(so-called secondary transfer).
The sheet of paper to which the color toner image or monochrome
toner image is transferred is thereafter pressed and heated by
fixing apparatus 8A. Accordingly, a color image or monochrome image
is formed on the sheet of paper, and the paper on which the color
image or monochrome image is formed is thereafter discharged from
apparatus body 2.
FIG. 2 is a schematic cross-sectional view of the fixing apparatus
in the present embodiment, and FIG. 1 is a schematic
partially-cutaway plan view of the fixing apparatus shown in FIG.
2. FIG. 4 is an exploded perspective view of a pad member and a
supporting member shown in FIGS. 2 and 3. Referring to FIGS. 2 to
4, a configuration of fixing apparatus 8A in the present embodiment
is described.
As shown in FIGS. 2 and 3, fixing apparatus 8A mainly includes a
pressing miler 10 serving as a pressing rotator, a fixing belt unit
20A serving as a heating rotator, different kinds of guides 31 to
33 for transporting a sheet of paper, a temperature sensor 40
detecting the temperature of a fixing belt 21 included in fixing
belt unit 20A, and a controller 50 controlling operation of a
heating source 24 included in fixing belt unit 20A.
Pressing roller 10 is formed of a metal core 11 made of aluminum
alloy, for example, and a rubber elastic layer 12 made of silicone
rubber, for example, and disposed to cover metal core 11. Pressing
roller 10 has a diameter of 25 mm, for example. Elastic layer 12
has a thickness of 3 mm, for example. Pressing roller 10 may
further have a release layer made of fluorine-based resin, for
example, and covering elastic layer 12.
Pressing miler 10 is disposed to face an outer circumferential
surface of fixing belt 21, and has axial opposite ends rotatably
supported by a shaft-support member (not shown). Pressing roller 10
is rotatably driven by drive means such as motor (not shown).
Pressing roller 10 is configured to be elastically biased toward
fixing belt unit 20A by a biasing member (not shown).
Fixing belt unit 20A mainly includes a pad member 22, a supporting
member 23, a pair of belt guides 25, and a high-reflectance member
26, in addition to fixing belt 21 and heating source 24 described
above.
Fixing belt 21 is endless and made up of a plurality of layers, for
example, in consideration of thermal resistance, strength, and
surface smoothness, for example. Specifically, fixing belt 21
includes a base layer of polyimide, for example, a rubber elastic
layer of silicone rubber, for example, and a release layer of
fluorine-based resin, for example. These multiple layers are
arranged successively in order of the base layer, the elastic
layer, and the release layer in the direction from inside to
outside of fixing belt 21. Fixing belt 21 has a circumferential
length of 25 mm, for example. The base layer has a thickness of 60
.mu.m, for example, the elastic layer has a thickness of 200 .mu.m,
for example, and the release layer has a thickness of 30 .mu.m, for
example.
Pad member 22 is formed of an elongate member extending in the
axial direction of pressing roller 10. Pad member 22 is disposed in
the space inside fixing belt 21. Pad member 22 has a substantially
C-shaped cross section orthogonal to the longitudinal direction.
Pad member 22 has a receiving surface 22a facing the inner
circumferential surface of fixing belt 21, and a supported surface
22b located opposite to receiving surface 22a. Pad member 22 is
made of liquid crystal polymer, for example.
Supporting member 23 is formed of an elongate member extending in
die axial direction of pressing roller 10, and mostly located in
the space inside fixing belt 21. Supporting member 23 is used to
support pad member 22, and includes a base 23a in a flat plate
shape and an erected wall 23b in a flat plate shape that are
disposed in the space inside fixing belt 21. Supporting member 23
is formed of a metal member such as electrogalvanized steel sheet
(SECC), for example.
As shown in FIGS. 2 to 4, in the present embodiment, erected wall
23b is erected from one of the ends, in the widthwise direction, of
base 23a. The widthwise direction is orthogonal to both the
longitudinal direction and the thickness direction of base 23a.
Supporting member 23 is thus formed of a single member having an
L-shaped cross section located m the space inside fixing belt
21.
As shown in FIG. 4, supporting member 23 is disposed so that one of
main surfaces of base 23a abuts on supported surface 22b of pad
member 22. In other words, pad member 22 and supporting member 23
are assembled so that pad member 22 covers base 23a of supporting
member 23. More specifically, pad member 22 has, at its
predetermined position, a latch portion 22c in the form of a hook,
for example. Latch portion 22c is engaged with base 23a of
supporting member 23 to fix pad member 22 to supporting member
23.
Erected wall 23b of supporting member 23 has opposite ends in the
longitudinal direction, and a fixing portion 23d is located at each
of these opposite ends. Fixing portions 23d are fixed to sidewalls
of a casing forming fixing apparatus 8A, or fixed to a chassis for
example disposed inside apparatus body 2 of image forming apparatus
1. Accordingly, pad member 22 is fixed in the space inside fixing
belt 21.
As shown in FIGS. 2 and 3, heating source 24 includes a long heater
24A and a short heater 24B that are a pair of rod-like heaters
extending in a direction parallel with the axial direction of
pressing roller 10. Heating source 24 is disposed in the space
inside fixing belt 21. Heating source 24 is used to heat fixing
belt 21. Long heater 24A and short heater 24B are each configured
as a halogen heater.
Long heater 24A has a heat generation part HG1 occupying a region
corresponding to a substantially entire region of pressing roller
10 in the axial direction. Heat generation part HG1 generates heat
to thereby heat fixing belt 21 mainly by means of its radiant heat.
Heat generation part HG1 has an axial length (i.e., width W1 shown
in FIG. 3) corresponding to the width of a sheet of paper having a
maximum width among sheets of paper of different sizes to be fed to
image forming apparatus 1.
Short heater 24B has a heat generation part HG2 occupying only a
region corresponding to a central portion of pressing roller 10 in
the axial direction. Heat generation part HG2 generates heat to
thereby heat fixing belt 21 mainly by means of its radiant heat.
Heat generation part HG2 has an axial length (i.e., width W2 shown
in FIG. 3) corresponding to the width of a sheet of paper having a
minimum width among sheets of paper of different sizes to be fed to
image forming apparatus 1.
In the space inside fixing belt 21, a pair of belt guides 25 is
arranged so that one belt guide 25 is located at one end of
pressing roller 10 and the other belt guide 25 is located at the
opposite end thereof in the axial direction. A cross-sectional
shape of the pair of belt guides 25 is substantially in the shape
of C. Fixing belt 21 is disposed to run slidably around the outer
circumferential surface of each belt guide. The pair of belt guides
25 is fixed to sidewalls of the casing forming fixing apparatus 8A,
or fixed to a chassis for example disposed inside apparatus body 2
of image forming apparatus 1. Thus, belt guides 25 guide rotation
of fixing belt 21.
High-reflectance member 26 is formed of a member having a surface
higher in reflectance than the surface of supporting member 23.
High-reflectance member 26 is formed of a reflecting plate made of
aluminum, for example. High-reflectance member 26 is used to
reflect light radiated from heating source 24 toward fixing belt
21. High-reflectance member 26 enables fixing belt 21 to be heated
more efficiently. High-reflectance member 26 is fixed to a
predetermined location of the surface of supporting member 23 by
means of adhesion or screw(s), for example.
Pressing miler 10 is configured to be elastically biased toward
fixing belt unit 20A by a biasing member (not shown), as described
above. As shown in FIGS. 2 and 3, with pressing roller 10
elastically biased toward fixing belt unit 20A by a biasing member
(not shown), fixing belt 21 is pressed against receiving surface
22a of pad member 22.
With fixing bell 21 pressed against receiving surface 22a of pad
member 22, pressing roller 10 is rotationally driven in the
direction indicated by an arrow A in FIG. 2, by drive means such as
motor (not shown) as described above. Accordingly, fixing belt 21
is rotated in the direction indicated by an arrow B shown in FIG. 2
while sliding on receiving surface 22a of pad member 22, following
rotation of pressing roller 10.
A nip portion N is thus formed between pressing roller 10 and the
outer circumferential surface of fixing belt 21. A sheet of paper
is transported through nip portion N. In other words, pressing
roller 10 and fixing belt unit 20A are arranged with paper
transport path 4 between roller 10 and fixing belt unit 20A, so
that nip portion N formed therebetween is located on transport path
4.
As shown in FIGS. 2 and 3, with fixing belt 21 pressed against
receiving surface 22a of pad member 22, pressing roller 10 and
fixing belt unit 20A are arranged in a pressing direction DR1. In
pressing direction DR1, fixing belt 21 is pressed against receiving
surface 22a of pad member 22. A direction orthogonal to pressing
direction DR1 and orthogonal to the axial direction of pressing
roller 10 is a transport direction DR2 in which a sheet of paper is
transported.
An entrance guide 31 is disposed at a position on transport path 4.
Entrance guide 31 is located upstream of nip portion N (i.e.,
located lower than nip portion N in FIG. 2) in paper transport
direction DR2. Entrance guide 31 serves as a guide for reliably
causing a sheet of paper transported along transport path 4 to
enter nip portion N.
A separation guide 32 and an exit guide 33 are also disposed at
respective positions on transport path 4. Separation guide 32 and
exit guide 33 are located downstream of nip portion N (i.e.,
located higher than nip portion N in FIG. 2) in paper transport
direction DR2. Separation guide 32 serves as a guide for causing a
sheet of paper in close contact with fixing belt 21 to be separated
from fixing belt 21 when the sheet of paper is discharged from nip
portion N. Exit guide 33 serves as a guide for causing the sheet of
paper separated from fixing belt 21 by separation guide 32 to
reliably return onto transport path 4.
As shown in FIG. 2, temperature sensor 40 is disposed to face the
outer circumferential surface of fixing belt 21, and located
upstream of nip portion N in the rotational direction of fixing
belt 21. Temperature sensor 40 is configured as a non-contact
sensor capable of measuring the temperature of fixing belt 21
without contacting fixing belt 21, for example.
Based on the temperature detected by temperature sensor 40,
controller 50 controls operation of heating source 24 made up of
long heater 24A and short heater 24B to adjust the temperature of
fixing belt 21 so that it falls in a predetermined temperature
range (150.degree. C. or more and 180.degree. C. or less, for
example) when fixing belt 21 passes through nip portion N.
As shown in FIG. 2, in fixing apparatus SA in the present
embodiment, erected wall 23b of supporting member 23 is disposed
upstream in paper transport direction DR2, from an intermediate
position (position indicated by reference P1 in the drawing) of nip
portion N in paper transport direction DR2, and erected wall 23b is
formed to be erected from base 23a in a direction away from the
position of pressing roller 10.
Erected wall 23b is formed to be relatively long. Specifically, the
length of erected wall 23b in the direction in which erected wall
23b is erected (i.e., the direction parallel with pressing
direction DR1) is larger than a predetermined size (approximately a
half or more of the diameter of fixing belt 21, for example).
Accordingly, the space inside fixing belt 21 is substantially
partitioned by erected wall 23b into an upstream space S1 located
upstream in paper transport direction DR2 and a downstream space S2
located downstream in paper transport direction DR2.
As described above, erected wall 23b is disposed upstream in paper
transport direction DR2, from the intermediate position of nip
portion N indicated by reference P1. Therefore, downstream space S2
is a larger space than upstream space S1. Heating source 24 is
disposed in downstream space S2 which is the larger space.
This configuration increases the efficiency of space usage,
relative to a configuration where the space inside the fixing belt
is partitioned by the supporting member into two spaces that are
substantially equal to each other, and thereby enables downsizing
of fixing belt unit 20A as a whole. It is therefore possible to
heat fixing belt 21 with less thermal energy. As the surface area
of fixing belt 21 is reduced, useless heat dissipation can be
prevented. This configuration can be used to produce a compact
fixing apparatus appropriate for energy saving.
In fixing apparatus 8A in the present embodiment, long heater 24A
and short heater 24B are arranged in pressing direction DR1. This
configuration enables increase of the efficiency of space usage,
relative to the case where other layouts of heating source 24 are
used, and thereby enables a compact fixing apparatus appropriate
for energy saving to be produced.
In fixing apparatus 8A in the present embodiment, long heater 24A
is located at a distance from pressing roller 10 longer than the
distance from pressing roller 10 to short heater 24B. In such a
configuration, long heater 24A used relatively more frequently in a
normal state of use is located at a distance from fixing belt 21
shorter than the distance from fixing belt 21 to short heater 24B
used relatively less frequently. Radiant heat generated by heating
source 24 can be used efficiently for heating fixing belt 21. Thus,
the fixing apparatus appropriate for energy saving can be
produced.
In fixing apparatus 8A in the present embodiment, high-reflectance
member 26 is attached to substantially the whole of the surface,
facing heating source 24, of base 23a and erected wall 23b of
supporting member 23. This configuration enables efficient
reflection, toward fixing belt 21, of light radiated from heating
source 24. A fixing apparatus appropriate for energy saving can
thus be produced.
In the present embodiment, high-reflectance member 26 is attached
to supporting member 23. Alternatively, the surface of supporting
member 23 may be plated in such a manner that a part of the surface
of supporting member 23 is a high-reflectance surface higher in
reflectance than the remaining part of the surface of supporting
member 23. This configuration also enables efficient reflection,
toward fixing belt 21, of light radiated from heating source 24. A
fixing apparatus appropriate for energy saving can thus be
produced.
The position where high-reflectance member 26 is attached and the
position where the high-reflectance surface is formed are not
particularly limited. This position may be the whole or a part of
the surface of base 23a facing heating source 24, or the whole or a
part of the surface of erected wall 23b facing heating source 24,
besides the above-described positions. High-reflectance member 26
may be additionally attached to the whole or a part of the surface,
failing to face heating source 24, of base 23a and erected wall
23b, or the whole or a part of the surface, failing to face heating
source 24, of base 23a and erected wall 23b may be additionally
formed as a high-reflectance surface.
In fixing apparatus 8A in the present embodiment, supporting member
23 has an L-shaped cross section extending continuously from one
end of base 23a in paper transport direction DR2 to one end of
erected wall 23b in pressing direction DR1. This configuration
enables supporting member 23 to be formed easily by bending a flat
metal sheet, for example, which produces the effect of reducing the
manufacture cost.
In fixing apparatus 8A in the present embodiment, supporting member
23 is formed of a single member. This configuration enables
reduction of the number of parts and facilitates assembly work,
which also produces the effect of reducing the manufacture
cost.
FIGS. 5 to 7 each illustrate an additional feature of the
configuration of the fixing apparatus shown in FIG. 2. In the
following, features of the configuration of fixing apparatus 8A in
the present embodiment, specifically additional features to be
particularly mentioned in addition to those described above, are
described in detail with reference to FIGS. 5 to 7 and FIG. 2.
Referring to FIGS. 2 and 5 to 7, "first specific portion 21A" and
"second specific portion 21B" are defined for the sake of
convenience of description. "First specific portion 21A" is a
portion of fixing belt 21, the portion defines a space where
heating source 24 is disposed, and the space is one of the spaces
into which the space inside the fixing belt 21 is partitioned by
erected wall 23b of supporting member 23. "Second specific portion
21B" is a portion of fixing belt 21, and the portion defines
upstream space S1. In the present embodiment, heating source 24 is
disposed in downstream space S2. First specific portion 21A and
second specific portion 21B are therefore different portions of
fixing belt 21.
In the fixing apparatus for which the fixing belt is used, as the
fixing belt rotates following rotation of the pressing roller, an
upstream portion of the fixing belt in the paper transport
direction (i.e., a portion to be introduced into the nip portion)
is drawn strongly by the pressing roller. Consequently, this
portion becomes a pulled state (tense state). Thus, in fixing
apparatus 8A in the present embodiment as well, as fixing belt 21
rotates following rotation of the pressing roller, the portion of
fixing belt 21 to be introduced into nip portion N (i.e.,
particularly a downstream part of second specific portion 21B in
the rotational direction of fixing belt 21) is in a tense
state.
In contrast, in the fixing apparatus for which the fixing belt is
used, as the fixing belt rotates following rotation of the pressing
roller, a downstream portion of the fixing belt in the paper
transport direction (i.e., a portion ejected from the nip portion)
is pushed out by the pressing roller. Consequently, this portion
becomes a sagged state (loose state). Thus, in fixing apparatus 8A
in the present embodiment as well, as fixing belt 21 rotates
following rotation of the pressing roller, the portion of fixing
belt 21 ejected from nip portion N (i.e., particularly an upstream
part of first specific portion 21A in the rotational direction of
fixing belt 21) is in a loose state.
Accordingly, in fixing apparatus 8A in the present embodiment, as
fixing belt 21 rotates following rotation of the pressing roller,
the trajectory of second specific portion 21B of fixing belt 21 is
relatively stable. In contrast, the trajectory of first specific
portion 21A of fixing belt 21 is unstable and tends to flap.
As shown in FIG. 5, in fixing apparatus 8A in the present
embodiment heating source 24 is disposed between the opposite ends
of pad member 22 in paper transport direction DR2, as seen in
pressing direction DR1. In other words, heating source 24 is
configured to be located within a region R1 shown in FIG. 12.
This configuration enables a sufficient distance between heating
source 24 and first specific portion 21A of fixing belt 21 to be
ensured. Therefore, even when first specific portion 21A of fixing
belt 21 flaps, first specific portion 21A can be prevented from
contacting or approaching heating source 24. Failure of fixing belt
21 due to excessive heating can thus be prevented.
As shown in FIG. 6, fixing apparatus 8A in the present embodiment
is configured so that a distance D1 between heating source 24 and
erected wall 23b of supporting member 21 in paper transport
direction DR2 is smaller than a distance D2 between heating source
24 and first specific portion 21A of fixing belt 21 in paper
transport direction DR2.
This configuration enables a sufficient distance between heating
source 24 and first specific portion 21A of fixing belt 21 to be
ensured. Therefore, even when first specific portion 21A of fixing
belt 21 flaps, first specific portion 21A can be prevented from
contacting or approaching heating source 24. Failure of fixing belt
21 due to excessive heating can thus be prevented.
As shown in FIG. 7, in fixing apparatus 8A in the present
embodiment a center position (position indicated by reference P2 in
the drawing) of heating source 24 in pressing direction DR1 is
located between the opposite ends of erected wall 23b of supporting
member 23 in pressing direction DR1, as seen in paper transport
direction DR2. In other words, the center position of heating
source 24 indicated by reference P2 is located within a region R2
shown in FIG. 7.
More specifically, in fixing apparatus 8A in the present
embodiment, the center position (position indicated by reference
P2A in the drawing) of long heater 24A in pressing direction DR1
and the center position (position indicated by reference P2B in the
drawing) of short heater 24B in pressing direction DR1 are both
located between the opposite ends of erected wall 23b of supporting
member 23 in pressing direction DR1, as seen in paper transport
direction DR2. Namely, the center position of long heater 24A
indicated by reference P2A and the center position of short heater
24B indicated by reference P2B are located within region R2 shown
in FIG. 7.
This configuration enables increase of the efficiency of space
usage, relative to the case where other layouts of heating source
24 are used, and thereby enables a compact fixing apparatus
appropriate for energy saving to be produced. Moreover, light
radiated from heating source 24 can be reflected highly efficiently
by the surface of supporting member 23 or by high-reflectance
member 26 attached to the surface of supporting member 23. This
light can be used efficiently for heating fixing belt 21. A fixing
apparatus appropriate for energy saving can thus be produced.
Referring to FIG. 2, in fixing apparatus 8A in the present
embodiment, temperature sensor 40 is located upstream of nip
portion N in the rotational direction of fixing belt 21, as
described above. More specifically, temperature sensor 40 is
located to face the outer circumferential surface of second
specific portion 21B of fixing belt 21 for detecting the
temperature of second specific portion 21B.
In this configuration, the temperature of fixing belt 21 detected
by temperature sensor 40 is not the temperature of the portion of
fixing belt 21 directly heated by heating source 24 but the portion
thereof that is not directly heated by heating source 24 (i.e., the
portion whose temperature is relatively stable) because shielded by
erected wall 23b of supporting member 23.
As compared with a configuration where the temperature sensor
detects the portion of the fixing belt that is directly heated by
the heating source, an error of the measured temperature due to low
accuracy of the positioning of temperature sensor 40, for example,
can be eliminated effectively. The temperature of fixing belt 21 at
nip portion N can be adjusted to fall within a predetermined
temperature range with high controllability. This configuration can
therefore be used to produce a fixing apparatus capable of causing
a toner image formed on a sheet of paper to be fixed precisely and
stably to the paper.
In view of the above, it is preferable to suppress increase of the
temperature of erected wall 23b so as to suppress undesired heating
of second specific portion 21B of fixing belt 21 through supporting
member 23, due to increase of the temperature of supporting member
23 resultant from heating of erected wall 23b of supporting member
23 by heating source 24. It is therefore preferable that the
position where high-reflectance member 26 is attached and the
position where a high-reflectance surface is formed should include
at least the whole or a part of the surface of erected wall 23b of
supporting member 23 that faces heating source 24, in order to
suppress increase of the temperature of erected wall 23b.
As seen from the foregoing, fixing apparatus 8A in the present
embodiment and image forming apparatus 1 including this fixing
apparatus can be implemented as a compact fixing apparatus
appropriate for energy saving and an image forming apparatus
including this fixing apparatus.
Second Embodiment
FIG. 8 is a schematic cross-sectional view of a fixing apparatus in
the second embodiment. In the following, fixing apparatus 8B in the
present embodiment is described with reference to FIG. 8. Fixing
apparatus 8B in the present embodiment is to be incorporated in
image forming apparatus 1 in the first embodiment, instead of
fixing apparatus SA in the first embodiment.
As shown in FIG. 8, fixing apparatus SB in the present embodiment
differs from fixing apparatus SA in the first embodiment only in
that the former includes a fixing belt unit 20B including a
supporting member 23 having a different shape. Specifically,
supporting member 23 includes a reinforcing auxiliary wall 23c1 in
addition to base 23a and erected wall 23b.
Reinforcing auxiliary wall 23c1 is erected from an end. This end is
one of the pair of ends of base 23a in the paper transport
direction, and different from the end from which erected wall 23b
extends. More specifically, reinforcing auxiliary wall 23c1 is
formed to protrude from base 23a in a direction away from the
position of pressing roller 10.
Reinforcing auxiliary wall 23c1 is configured to have a length in
the erecting direction (i.e., direction parallel with pressing
direction DR1) sufficiently smaller than the length of erected wall
23b in the erecting direction (i.e., direction parallel with
pressing direction DR1). Reinforcing auxiliary wall 23c1 is thus
configured so as not to interfere with heating source 24 disposed
in downstream space S2.
Supporting member 23 thus includes reinforcing auxiliary wall 23c1
erected from base 23a in addition to base 23a and erected wall 23b,
which significantly increases the rigidity of supporting member
23.
Fixing apparatus 8B having the above-described configuration and
image forming apparatus 1 including this fixing apparatus provide
the effects described in connection with the first embodiment, and
further provide the effect that undesired deformation of supporting
member 23 due to the pressing force applied by pressing roller 10
can be prevented more reliably.
This configuration enables easy formation of supporting member 23
by bending a flat metal sheet, for example, which produces the
effect that the manufacture cost can be reduced, and also enables
supporting member 23 to be formed of a single member, which also
produces the effect that the manufacture cost can be reduced.
Third Embodiment
FIG. 9 is a schematic cross-sectional view of a fixing apparatus in
the third embodiment. In the following, fixing apparatus 8C in the
present embodiment is described with reference to FIG. 9. Fixing
apparatus 8C in the present embodiment is to be incorporated in
image forming apparatus 1 in the first embodiment, instead of
fixing apparatus 8A in the first embodiment.
As shown in FIG. 9, fixing apparatus 8C in the present embodiment
differs from fixing apparatus 8A in the first embodiment only in
that the former includes a fixing belt unit 20C including a
supporting member 23 having a different shape. Specifically,
supporting member 23 includes a reinforcing auxiliary wall 23c2 in
addition to base 23a and erected wall 23b.
Reinforcing auxiliary wall 23c2 is erected from a position of base
23a. This position is any position between a pair of ends of base
23a in the paper transport direction, but other than the pair of
ends of base 23a. More specifically, reinforcing auxiliary wall
23c2 is formed to protrude from base 23a in a direction away from
the position of pressing roller 10.
Reinforcing auxiliary wall 23c2 is configured to have a length in
the erecting direction (i.e., direction parallel with pressing
direction DR1) sufficiently smaller than the length of erected wall
23b in the erecting direction (i.e., direction parallel with
pressing direction DR1). Reinforcing auxiliary wall 23c2 is thus
configured so as not to interfere with heating source 24 disposed
in downstream space S2.
Supporting member 23 thus includes reinforcing auxiliary wall 23c2
erected from base 23a in addition to base 23a and erected wall 23b,
which significantly increases the rigidity of supporting member
23.
Fixing apparatus 8C having the above-described configuration and
image forming apparatus 1 including this fixing apparatus provide
the effects described in connection with the first embodiment, and
further provide the effect that undesired deformation of supporting
member 23 due to the pressing force applied by pressing roller 10
can be prevented more reliably.
This configuration enables supporting member 23 to be formed of a
single member, which produces the effect that the manufacture cost
can be reduced.
Fourth Embodiment
FIG. 10 is a schematic cross-sectional view of a fixing apparatus
in the fourth embodiment. In the following, fixing apparatus 8D in
the present embodiment is described with reference to FIG. 10.
Fixing apparatus 8D in the present embodiment is to be incorporated
in image forming apparatus 1 in the first embodiment, instead of
fixing apparatus 8A in the first embodiment.
As shown in FIG. 10, fixing apparatus 8D in the present embodiment
differs from fixing apparatus 8A in the first embodiment only in
that the former includes a fixing belt unit 20D including a
supporting member 23 having a different shape. Specifically, fixing
belt unit 20D differs from the above-described one in the position
where erected wall 23b of supporting member 23 is formed on base
23a.
More specifically, erected wall 23b is erected from a position of
base 23a. This position is any position between a pair of ends of
base 23a in the paper transport direction, but other than the pair
of ends of base 23a. Erected wall 23b is formed to be erected from
base 23a in the direction away from the position of pressing roller
10.
In the present embodiment as well, erected wall 23b is disposed
upstream in paper transport direction DR2, from the intermediate
position of nip portion N indicated by reference P1. Downstream
space S2 is therefore a larger space than upstream space S1.
Heating source 24 is disposed in downstream space S2 which is the
larger space.
Fixing apparatus 8D having the above-described configuration and
image forming apparatus 1 including this fixing apparatus provide
the effects described in connection with the first embodiment. A
compact fixing apparatus appropriate for energy saving and an image
forming apparatus including the fixing apparatus can thus be
implemented.
This configuration also enables supporting member 23 to be formed
of a single member, which produces the effect that the manufacture
cost can be reduced.
Fifth Embodiment
FIG. 11 is a schematic cross-sectional view of a fixing apparatus
in the fifth embodiment. In the following, fixing apparatus 8E in
the present embodiment is described with reference to FIG. 11.
Fixing apparatus 8E in the present embodiment is to be incorporated
m image forming apparatus 1 in the first embodiment, instead of
fixing apparatus 8A in the first embodiment.
As shown in FIG. 11, fixing apparatus SE in the present embodiment
differs from fixing apparatus 8A in the first embodiment in that a
fixing belt unit 20E of the former includes a supporting member 23
having a different shape and a heating source 24 disposed at a
different position.
Specifically, erected wall 23b of supporting member 23 is disposed
downstream in paper transport direction DR2, from the intermediate
position (position indicated by reference P1 in the drawing) of nip
portion N in paper transport direction DR2, and erected wall 23b is
formed to be erected from base 23a in the direction away from the
position of pressing roller 10.
Erected wall 23b is formed to be relatively long. Specifically, the
length of erected wall 23b in the direction in which erected wall
23b is erected (i.e., the direction parallel with pressing
direction DR1) is larger than a predetermined size (approximately a
half or more of the diameter of fixing belt 21, for example).
Accordingly, the space inside fixing belt 21 is substantially
partitioned by erected wall 23b into an upstream space S1 located
upstream in paper transport direction DR2 and a downstream space S2
located downstream in paper transport direction DR2.
As described above, erected wall 23b is disposed downstream in
paper transport direction DR2, from the intermediate position of
nip portion N indicated by reference P1. Therefore, upstream space
S1 is a larger space than downstream space S2. Heating source 24 is
disposed in upstream space S1 which is the larger space.
This configuration increases the efficiency of space usage,
relative to a configuration where the space inside the fixing belt
is partitioned by the supporting member into two spaces that are
substantially equal to each other, and thereby enables downsizing
of fixing belt unit 20E as a whole. It is therefore possible to
heat fixing belt 21 with less thermal energy. As the surface area
of fixing apparatus 21 is reduced, useless heat dissipation can be
prevented. This configuration can be used to produce a compact
fixing apparatus appropriate for energy saving.
This configuration enables supporting member 23 to be formed easily
by bending a flat metal sheet, for example, which produces the
effect that the manufacture cost can be reduced. Supporting member
23 can be formed of a single member, which also provides the effect
that the manufacture cost can be reduced.
FIGS. 12 to 14 each illustrate an additional feature of the
configuration of the fixing apparatus shown in FIG. 11. In the
following, features of the configuration of fixing apparatus 8E in
the present embodiment, specifically additional features to be
particularly mentioned in addition to those described above, are
described in detail with reference to FIGS. 12 to 14 and FIG.
11.
Referring to FIGS. 11 to 14, like the first embodiment described
above. "first specific portion 21A" and "second specific portion
21B" are defined in the following way. "First specific portion" is
a portion of fixing belt 21 defining the space where heating source
24 is disposed, of the inner space of fixing belt 21 partitioned by
erected wall 23b of supporting member 23, and "second specific
portion 21B" is a portion of fixing belt 21 defining upstream space
S1. In fixing apparatus 8E in the present embodiment, heating
source 24 is disposed in upstream space S1, and therefore,
above-defined first specific portion 21A and second specific
portion 21B refer to the same portion of fixing belt 21. Therefore,
for the sake of convenience, this portion of fixing belt 21 is
referred to as first specific portion 21A only. In the present
embodiment, the portion of fixing belt 21 defining downstream space
S2 is defined as "third specific portion 21C."
In this case, in fixing apparatus 8E in the present embodiment, as
fixing belt 21 rotates following rotation of the pressing roller,
the trajectory of first specific portion 21A of fixing belt 21 is
relatively stable. In contrast, the trajectory of third specific
portion 21C of fixing belt 21 is unstable and tends to flap.
As shown in FIG. 11, in fixing apparatus SE in the present
embodiment, heating source 24 is disposed between the opposite ends
of pad member 22 in paper transport direction DR2, as seen in
pressing direction DR1. In other words, heating source 24 is
configured to be located within a region R1 shown in FIG. 12.
This configuration enables a sufficient distance between heating
source 24 and first specific portion 21A of fixing belt 21 to be
ensured. Therefore, first specific portion 21A of fixing belt 21
can be prevented from contacting or approaching heating source 24.
Failure of fixing belt 21 due to excessive heating can thus be
prevented.
This configuration also enables a sufficient distance between
heating source 24 and third specific portion 21C of fixing belt 21
to be ensured. Therefore, even when third specific portion 21C of
fixing belt 21 flaps, third specific portion 21C can be prevented
from contacting or approaching heating source 24. Failure of fixing
belt 21 due to excessive heating can thus be prevented.
As shown in FIG. 13, fixing apparatus 8E in the present embodiment
is configured so that a distance D1 between heating source 24 and
erected wall 23b of supporting member 23 in paper transport
direction DR2 is smaller than a distance D2 between heating source
24 and first specific portion 21A of fixing belt 21 in paper
transport direction DR2.
This configuration enables a sufficient distance between heating
source 24 and first specific portion 21A of fixing belt 21 to be
ensured. Therefore, first specific portion 21A of fixing belt 21
can be prevented from contacting or approaching heating source 24.
Failure of fixing belt 21 due to excessive heating can thus be
prevented.
In this configuration, erected wall 23b of supporting member 23 is
located between heating source 24 and third specific portion 21C of
fixing belt 21 to thereby shield third specific portion 21C from
heating source 24. Therefore, even when third specific portion 21C
of fixing belt 21 flaps, third specific portion 21C can be
prevented from contacting or approaching heating source 24. Failure
of fixing belt 21 due to excessive heating can thus be
prevented.
As shown in FIG. 14, in fixing apparatus 8E in the present
embodiment, a center position (position indicated by reference P2
in the drawing) of heating source 24 in pressing direction DR1 is
located between the opposite ends of erected wall 23b of supporting
member 23 in pressing direction DR1, as seen in paper transport
direction DR2. In other words, the center position of heating
source 24 indicated by reference P2 is located within a region R2
shown in FIG. 14.
More specifically, in fixing apparatus RE in the present
embodiment, the center position (position indicated by reference
P2A in the drawing) of long heater 24A in pressing direction DR1
and the center position (position indicated by reference P2B in the
drawing) of short heater 24B in pressing direction DR1 are both
located between the opposite ends of erected wall 23b of supporting
member 23 in pressing direction DR1, as seen in paper transport
direction DR2 Namely, the center position of long heater 24A
indicated by reference P2A and the center position of short heater
24B indicated by reference P2B are located within region R2 shown
in FIG. 14.
This configuration enables increase of the efficiency of space
usage, relative to the case where other layouts of heating source
24 are used, and thereby enables a compact fixing apparatus
appropriate for energy saving to be produced. Moreover, light
radiated from heating source 24 can be reflected highly efficiently
by the surface of supporting member 23 or by high-reflectance
member 26 attached to the surface of supporting member 23. This
light can be used efficiently for heating fixing belt 21. A fixing
apparatus appropriate for energy saving can thus be produced.
As seen from the foregoing, fixing apparatus RE in the present
embodiment and image forming apparatus 1 including this fixing
apparatus can be implemented as a compact fixing apparatus
appropriate for energy saving and an image forming apparatus
including this fixing apparatus.
The above description of the first to fifth embodiments illustrates
the case where the present invention is applied to the so-called
tandem-type electrophotographic color printer as well as the fixing
apparatus included in the color printer. Uses to which the present
invention is applied, however, are not limited to them. The present
invention is also applicable to various types of
electrophotographic image forming apparatuses and the fixing
apparatus included in any of these electrophotographic image
forming apparatuses.
Respective configurations of components such as the pressing
rotator the heating source, and different kinds of guides described
above in connection with the first to fifth embodiments may be
modified appropriately within the scope of the invention.
While the above description of the second and third embodiments
illustrates the case where one reinforcing auxiliary wall is
erected from the base of the supporting member in the direction
away from the position of the pressing rotator, more than one
reinforcing auxiliary wall may be disposed and more than one
reinforcing auxiliary wall may be erected toward the pressing
rotator. Further, the reinforcing auxiliary wall may be disposed on
the erected wall of the supporting member.
The characteristic features illustrated in connection with the
first to fifth embodiments may be combined within the scope of the
present invention.
Although embodiments of the present invention have been described
and illustrated in detail, it is clearly understood that the same
is by way of illustration and example only, not by way of
limitation, and the scope of the present invention should be
interpreted by terms of the appended claims.
* * * * *